/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell (papowell@astart.com)
 * It may be used for any purpose as long as this notice remains intact
 * on all source code distributions
 */

/**************************************************************
* Original:
* Patrick Powell Tue Apr 11 09:48:21 PDT 1995
* A bombproof version of doprnt (dopr) included.
* Sigh.  This sort of thing is always nasty do deal with.  Note that
* the version here does not include floating point...
*
* snprintf() is used instead of sprintf() as it does limit checks
* for string length.  This covers a nasty loophole.
*
* The other functions are there to prevent NULL pointers from
* causing nast effects.
*
* More Recently:
*  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
*  This was ugly.  It is still ugly.  I opted out of floating point
*  numbers, but the formatter understands just about everything
*  from the normal C string format, at least as far as I can tell from
*  the Solaris 2.5 printf(3S) man page.
*
*  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
*    Ok, added some minimal floating point support, which means this
*    probably requires libm on most operating systems.  Don't yet
*    support the exponent (e, E) and sigfig (g, G).  Also, fmtint()
*    was pretty badly broken, it just wasn't being exercised in ways
*    which showed it, so that's been fixed.  Also, formated the code
*    to mutt conventions, and removed dead code left over from the
*    original.  Also, there is now a builtin-test, just compile with:
*           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
*    and run snprintf for results.
*
*  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
*    The PGP code was using unsigned hexadecimal formats.
*    Unfortunately, unsigned formats simply didn't work.
*
*  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
*    The original code assumed that both snprintf() and vsnprintf() were
*    missing.  Some systems only have snprintf() but not vsnprintf(), so
*    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
*
*  Andrew Tridgell (tridge@samba.org) Oct 1998
*    fixed handling of %.0f
*    added test for HAVE_LONG_DOUBLE
*
*  Chris Kirmse (ckirmse@yahoo.com) May 2003
*    fixed handling of leading zeros in the fractional part of a float.
*
*  Andrea Mazzoleni May 2003
*    added minimal support for %g.
*
**************************************************************/

/* #include "config.h" */
#define HAVE_STDARG_H

/* moved above the #ifdef to avoid warning about empty c-files */
#include <string.h>
#include <ctype.h>
#include <sys/types.h>

#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)


/* Define this as a fall through, HAVE_STDARG_H is probably already set */
#define HAVE_VARARGS_H


/* varargs declarations: */

#if defined(HAVE_STDARG_H)
#include <stdarg.h>
#define HAVE_STDARGS     /* let's hope that works everywhere (mj) */
#define VA_LOCAL_DECL   va_list ap
#define VA_START(f)     va_start(ap, f)
#define VA_SHIFT(v, t)  ;    /* no-op for ANSI */
#define VA_END          va_end(ap)
#else
#if defined(HAVE_VARARGS_H)
#include <varargs.h>
#undef HAVE_STDARGS
#define VA_LOCAL_DECL   va_list ap
#define VA_START(f)     va_start(ap)        /* f is ignored! */
#define VA_SHIFT(v, t) v = va_arg(ap, t)
#define VA_END        va_end(ap)
#else
/*XX ** NO VARARGS ** XX*/
#endif
#endif

#ifdef HAVE_LONG_DOUBLE
#define LDOUBLE long double
#else
#define LDOUBLE double
#endif

int snprintf(char *str, size_t count, const char *fmt, ...);
int vsnprintf(char *str, size_t count, const char *fmt, va_list arg);

static void dopr(char *buffer, size_t maxlen, const char *format,
	va_list args);
static void fmtstr(char *buffer, size_t *currlen, size_t maxlen,
	char *value, int flags, int min, int max);
static void fmtint(char *buffer, size_t *currlen, size_t maxlen,
	long value, int base, int min, int max, int flags);
static void fmtfp(char *buffer, size_t *currlen, size_t maxlen,
	LDOUBLE fvalue, int min, int max, int flags);
static void fmtfpg(char *buffer, size_t *currlen, size_t maxlen,
	LDOUBLE fvalue, int min, int max, int flags);
static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c);

/*
 * dopr(): poor man's version of doprintf
 */

/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS   1
#define DP_S_MIN     2
#define DP_S_DOT     3
#define DP_S_MAX     4
#define DP_S_MOD     5
#define DP_S_CONV    6
#define DP_S_DONE    7

/* format flags - Bits */
#define DP_F_MINUS      (1 << 0)
#define DP_F_PLUS       (1 << 1)
#define DP_F_SPACE      (1 << 2)
#define DP_F_NUM        (1 << 3)
#define DP_F_ZERO       (1 << 4)
#define DP_F_UP         (1 << 5)
#define DP_F_UNSIGNED   (1 << 6)

/* Conversion Flags */
#define DP_C_SHORT   1
#define DP_C_LONG    2
#define DP_C_LDOUBLE 3

#define char_to_int(p) (p - '0')
#define MAX(p, q) ((p >= q) ? p : q)

static void dopr(char *buffer, size_t maxlen, const char *format, va_list args)
{
	char ch;
	long value;
	LDOUBLE fvalue;
	char *strvalue;
	int min;
	int max;
	int state;
	int flags;
	int cflags;
	size_t currlen;

	state = DP_S_DEFAULT;
	currlen = flags = cflags = min = 0;
	max = -1;
	ch = *format++;

	while (state != DP_S_DONE) {
		if ((ch == '\0') || (currlen >= maxlen))
			state = DP_S_DONE;

		switch (state) {
		case DP_S_DEFAULT:
			if (ch == '%')
				state = DP_S_FLAGS;
			else
				dopr_outch(buffer, &currlen, maxlen, ch);
			ch = *format++;
			break;
		case DP_S_FLAGS:
			switch (ch) {
			case '-':
				flags |= DP_F_MINUS;
				ch = *format++;
				break;
			case '+':
				flags |= DP_F_PLUS;
				ch = *format++;
				break;
			case ' ':
				flags |= DP_F_SPACE;
				ch = *format++;
				break;
			case '#':
				flags |= DP_F_NUM;
				ch = *format++;
				break;
			case '0':
				flags |= DP_F_ZERO;
				ch = *format++;
				break;
			default:
				state = DP_S_MIN;
				break;
			}
			break;
		case DP_S_MIN:
			if (isdigit(ch)) {
				min = 10 * min + char_to_int(ch);
				ch = *format++;
			} else if (ch == '*') {
				min = va_arg(args, int);
				ch = *format++;
				state = DP_S_DOT;
			} else
				state = DP_S_DOT;
			break;
		case DP_S_DOT:
			if (ch == '.') {
				state = DP_S_MAX;
				ch = *format++;
			} else
				state = DP_S_MOD;
			break;
		case DP_S_MAX:
			if (isdigit(ch)) {
				if (max < 0)
					max = 0;
				max = 10 * max + char_to_int(ch);
				ch = *format++;
			} else if (ch == '*') {
				max = va_arg(args, int);
				ch = *format++;
				state = DP_S_MOD;
			} else
				state = DP_S_MOD;
			break;
		case DP_S_MOD:
			/* Currently, we don't support Long Long, bummer */
			switch (ch) {
			case 'h':
				cflags = DP_C_SHORT;
				ch = *format++;
				break;
			case 'l':
				cflags = DP_C_LONG;
				ch = *format++;
				break;
			case 'L':
				cflags = DP_C_LDOUBLE;
				ch = *format++;
				break;
			default:
				break;
			}
			state = DP_S_CONV;
			break;
		case DP_S_CONV:
			switch (ch) {
			case 'd':
			case 'i':
				if (cflags == DP_C_SHORT)
					value = va_arg(args, int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, long int);
				else
					value = va_arg(args, int);
				fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
				break;
			case 'o':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg(args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, unsigned long int);
				else
					value = va_arg(args, unsigned int);
				fmtint(buffer, &currlen, maxlen, value, 8, min, max, flags);
				break;
			case 'u':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg(args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, unsigned long int);
				else
					value = va_arg(args, unsigned int);
				fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
				break;
			case 'X':
				flags |= DP_F_UP;
			case 'x':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg(args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, unsigned long int);
				else
					value = va_arg(args, unsigned int);
				fmtint(buffer, &currlen, maxlen, value, 16, min, max, flags);
				break;
			case 'f':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, LDOUBLE);
				else
					fvalue = va_arg(args, double);
				/* um, floating point? */
				fmtfp(buffer, &currlen, maxlen, fvalue, min, max, flags);
				break;
			case 'E':
				flags |= DP_F_UP;
			case 'e':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, LDOUBLE);
				else
					fvalue = va_arg(args, double);
				break;
			case 'G':
				flags |= DP_F_UP;
			case 'g':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, LDOUBLE);
				else
					fvalue = va_arg(args, double);
				fmtfpg(buffer, &currlen, maxlen, fvalue, min, max, flags);
				break;
			case 'c':
				dopr_outch(buffer, &currlen, maxlen, va_arg(args, int));
				break;
			case 's':
				strvalue = va_arg(args, char *);
				if (max < 0)
					max = maxlen; /* ie, no max */
				fmtstr(buffer, &currlen, maxlen, strvalue, flags, min, max);
				break;
			case 'p':
				strvalue = va_arg(args, void *);
				fmtint(buffer, &currlen, maxlen, (long)strvalue, 16, min, max, flags);
				break;
			case 'n':
				if (cflags == DP_C_SHORT) {
					short int *num;
					num = va_arg(args, short int *);
					*num = currlen;
				} else if (cflags == DP_C_LONG) {
					long int *num;
					num = va_arg(args, long int *);
					*num = currlen;
				} else {
					int *num;
					num = va_arg(args, int *);
					*num = currlen;
				}
				break;
			case '%':
				dopr_outch(buffer, &currlen, maxlen, ch);
				break;
			case 'w':
				/* not supported yet, treat as next char */
				ch = *format++;
				break;
			default:
				/* Unknown, skip */
				break;
			}
			ch = *format++;
			state = DP_S_DEFAULT;
			flags = cflags = min = 0;
			max = -1;
			break;
		case DP_S_DONE:
			break;
		default:
			/* hmm? */
			break; /* some picky compilers need this */
		}
	}
	if (currlen < maxlen - 1)
		buffer[currlen] = '\0';
	else
		buffer[maxlen - 1] = '\0';
}

static void fmtstr(char *buffer, size_t *currlen, size_t maxlen,
	char *value, int flags, int min, int max)
{
	int padlen, strln; /* amount to pad */
	int cnt = 0;

	if (value == 0) {
		value = "<NULL>";
	}

	for (strln = 0; value[strln]; ++strln) ; /* strlen */
	padlen = min - strln;
	if (padlen < 0)
		padlen = 0;
	if (flags & DP_F_MINUS)
		padlen = -padlen; /* Left Justify */

	while ((padlen > 0) && (cnt < max)) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		--padlen;
		++cnt;
	}
	while (*value && (cnt < max)) {
		dopr_outch(buffer, currlen, maxlen, *value++);
		++cnt;
	}
	while ((padlen < 0) && (cnt < max)) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		++padlen;
		++cnt;
	}
}

/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */

static void fmtint(char *buffer, size_t *currlen, size_t maxlen,
	long value, int base, int min, int max, int flags)
{
	int signvalue = 0;
	unsigned long uvalue;
	char convert[20];
	int place = 0;
	int spadlen = 0; /* amount to space pad */
	int zpadlen = 0; /* amount to zero pad */
	int caps = 0;

	if (max < 0)
		max = 0;

	uvalue = value;

	if (!(flags & DP_F_UNSIGNED)) {
		if (value < 0) {
			signvalue = '-';
			uvalue = -value;
		} else if (flags & DP_F_PLUS) /* Do a sign (+/i) */
			signvalue = '+';
		else if (flags & DP_F_SPACE)
			signvalue = ' ';
	}

	if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */

	do {
		convert[place++] =
			(caps ? "0123456789ABCDEF" : "0123456789abcdef")
			[uvalue % (unsigned)base  ];
		uvalue = (uvalue / (unsigned)base);
	} while (uvalue && (place < 20));
	if (place == 20) place--;
	convert[place] = 0;

	zpadlen = max - place;
	spadlen = min - MAX(max, place) - (signvalue ? 1 : 0);
	if (zpadlen < 0) zpadlen = 0;
	if (spadlen < 0) spadlen = 0;
	if (flags & DP_F_ZERO) {
		zpadlen = MAX(zpadlen, spadlen);
		spadlen = 0;
	}
	if (flags & DP_F_MINUS)
		spadlen = -spadlen; /* Left Justifty */

#ifdef DEBUG_SNPRINTF
	dprint(1, (debugfile, "zpad: %d, spad: %d, min: %d, max: %d, place: %d\n",
		zpadlen, spadlen, min, max, place));
#endif

	/* Spaces */
	while (spadlen > 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		--spadlen;
	}

	/* Sign */
	if (signvalue)
		dopr_outch(buffer, currlen, maxlen, signvalue);

	/* Zeros */
	if (zpadlen > 0) {
		while (zpadlen > 0) {
			dopr_outch(buffer, currlen, maxlen, '0');
			--zpadlen;
		}
	}

	/* Digits */
	while (place > 0)
		dopr_outch(buffer, currlen, maxlen, convert[--place]);

	/* Left Justified spaces */
	while (spadlen < 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		++spadlen;
	}
}

static LDOUBLE abs_val(LDOUBLE value)
{
	LDOUBLE result = value;

	if (value < 0)
		result = -value;

	return result;
}

static LDOUBLE pow10(int exp)
{
	LDOUBLE result = 1;

	while (exp) {
		result *= 10;
		exp--;
	}

	return result;
}

static long round(LDOUBLE value)
{
	long intpart;

	intpart = value;
	value = value - intpart;
	if (value >= 0.5)
		intpart++;

	return intpart;
}

static void fmtfp(char *buffer, size_t *currlen, size_t maxlen,
	LDOUBLE fvalue, int min, int max, int flags)
{
	int signvalue = 0;
	LDOUBLE ufvalue;
	char iconvert[20];
	char fconvert[20];
	int iplace = 0;
	int fplace = 0;
	int padlen = 0; /* amount to pad */
	int zpadlen = 0;
	int caps = 0;
	long intpart;
	long fracpart;

	/*
	 * AIX manpage says the default is 0, but Solaris says the default
	 * is 6, and sprintf on AIX defaults to 6
	 */
	if (max < 0)
		max = 6;

	ufvalue = abs_val(fvalue);

	if (fvalue < 0)
		signvalue = '-';
	else if (flags & DP_F_PLUS) /* Do a sign (+/i) */
		signvalue = '+';
	else if (flags & DP_F_SPACE)
		signvalue = ' ';

#if 0
	if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
#endif

	intpart = ufvalue;

	/*
	 * Sorry, we only support 9 digits past the decimal because of our
	 * conversion method
	 */
	if (max > 9)
		max = 9;

	/* We "cheat" by converting the fractional part to integer by
	 * multiplying by a factor of 10
	 */
	fracpart = round((pow10(max)) * (ufvalue - intpart));

	if (fracpart >= pow10(max)) {
		intpart++;
		fracpart -= pow10(max);
	}

#ifdef DEBUG_SNPRINTF
	dprint(1, (debugfile, "fmtfp: %f =? %d.%d\n", fvalue, intpart, fracpart));
#endif

	/* Convert integer part */
	do {
		iconvert[iplace++] =
			(caps ? "0123456789ABCDEF" : "0123456789abcdef")[intpart % 10];
		intpart = (intpart / 10);
	} while (intpart && (iplace < 20));
	if (iplace == 20) iplace--;
	iconvert[iplace] = 0;

	/* Convert fractional part */
	do {
		fconvert[fplace++] =
			(caps ? "0123456789ABCDEF" : "0123456789abcdef")[fracpart % 10];
		fracpart = (fracpart / 10);
	} while (fracpart && (fplace < 20));
	if (fplace == 20) fplace--;
	fconvert[fplace] = 0;

	/* -1 for decimal point, another -1 if we are printing a sign */
	padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
	zpadlen = max - fplace;
	if (zpadlen < 0)
		zpadlen = 0;
	if (padlen < 0)
		padlen = 0;
	if (flags & DP_F_MINUS)
		padlen = -padlen; /* Left Justifty */

	if ((flags & DP_F_ZERO) && (padlen > 0)) {
		if (signvalue) {
			dopr_outch(buffer, currlen, maxlen, signvalue);
			--padlen;
			signvalue = 0;
		}
		while (padlen > 0) {
			dopr_outch(buffer, currlen, maxlen, '0');
			--padlen;
		}
	}
	while (padlen > 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		--padlen;
	}
	if (signvalue)
		dopr_outch(buffer, currlen, maxlen, signvalue);

	while (iplace > 0)
		dopr_outch(buffer, currlen, maxlen, iconvert[--iplace]);

	/*
	 * Decimal point.  This should probably use locale to find the correct
	 * char to print out.
	 */
	if (max > 0) {
		int i;
		dopr_outch(buffer, currlen, maxlen, '.');

		/* print leading zeros of the fractional part */
		for (i = 0; i < max - fplace; i++) {
			dopr_outch(buffer, currlen, maxlen, '0');
			zpadlen--;
		}

		while (fplace > 0)
			dopr_outch(buffer, currlen, maxlen, fconvert[--fplace]);
	}

	while (zpadlen > 0) {
		dopr_outch(buffer, currlen, maxlen, '0');
		--zpadlen;
	}

	while (padlen < 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		++padlen;
	}
}

static void fmtfpg(char *buffer, size_t *currlen, size_t maxlen,
	LDOUBLE fvalue, int min, int max, int flags)
{
	size_t len = *currlen;
	size_t i;
	fmtfp(buffer, currlen, maxlen, fvalue, min, max, flags);
	/* remove ending 0 after '.' */
	for (i = len; i < *currlen; ++i)
		if (buffer[i] == '.')
			break;
	if (i < *currlen) {
		while (*currlen > 0 && buffer[*currlen - 1] == '0')
			--*currlen;
		if (*currlen > 0 && buffer[*currlen - 1] == '.')
			--*currlen;
	}
}

static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c)
{
	if (*currlen < maxlen)
		buffer[(*currlen)++] = c;
}

#ifndef HAVE_VSNPRINTF
int vsnprintf(char *str, size_t count, const char *fmt, va_list args)
{
	str[0] = 0;
	dopr(str, count, fmt, args);
	return strlen(str);
}
#endif /* !HAVE_VSNPRINTF */

#ifndef HAVE_SNPRINTF
/* VARARGS3 */
#ifdef HAVE_STDARGS
int snprintf(char *str, size_t count, const char *fmt, ...)
#else
int snprintf(va_alist) va_dcl
#endif
{
#ifndef HAVE_STDARGS
	char *str;
	size_t count;
	char *fmt;
#endif
	VA_LOCAL_DECL;

	VA_START(fmt);
	VA_SHIFT(str, char *);
	VA_SHIFT(count, size_t);
	VA_SHIFT(fmt, char *);
	(void)vsnprintf(str, count, fmt, ap);
	VA_END;
	return strlen(str);
}
#endif /* !HAVE_SNPRINTF */

#ifdef TEST_SNPRINTF
#ifndef LONG_STRING
#define LONG_STRING 1024
#endif
int main(void)
{
	char buf1[LONG_STRING];
	char buf2[LONG_STRING];
	char *fp_fmt[] = {
		"%-1.5f",
		"%1.5f",
		"%123.9f",
		"%10.5f",
		"% 10.5f",
		"%+22.9f",
		"%+4.9f",
		"%01.3f",
		"%4f",
		"%3.1f",
		"%3.2f",
		"%.0f",
		"%.1f",
		NULL
	};
	double fp_nums[] = { -1.5, 134.21, 91340.2, 341.1234, 0203.9, 0.96, 0.996,
			     0.9996, 1.996, 4.136, 1.05, 0 };
	char *int_fmt[] = {
		"%-1.5d",
		"%1.5d",
		"%123.9d",
		"%5.5d",
		"%10.5d",
		"% 10.5d",
		"%+22.33d",
		"%01.3d",
		"%4d",
		NULL
	};
	long int_nums[] = { -1, 134, 91340, 341, 0203, 0 };
	int x, y;
	int fail = 0;
	int num = 0;

	printf("Testing snprintf format codes against system sprintf...\n");

	for (x = 0; fp_fmt[x] != NULL; x++)
		for (y = 0; fp_nums[y] != 0; y++) {
			snprintf(buf1, sizeof(buf1), fp_fmt[x], fp_nums[y]);
			sprintf(buf2, fp_fmt[x], fp_nums[y]);
			if (strcmp(buf1, buf2)) {
				printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf  = %s\n",
					fp_fmt[x], buf1, buf2);
				fail++;
			}
			num++;
		}

	for (x = 0; int_fmt[x] != NULL; x++)
		for (y = 0; int_nums[y] != 0; y++) {
			snprintf(buf1, sizeof(buf1), int_fmt[x], int_nums[y]);
			sprintf(buf2, int_fmt[x], int_nums[y]);
			if (strcmp(buf1, buf2)) {
				printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf  = %s\n",
					int_fmt[x], buf1, buf2);
				fail++;
			}
			num++;
		}
	printf("%d tests failed out of %d.\n", fail, num);
}
#endif /* SNPRINTF_TEST */

#endif /* !HAVE_SNPRINTF */

